It isn't that complex. The idea behind the metaphor isn't to communicate what an uncovered call is, it's to illuminate what technical debt really means. It's a philosophical analysis describing that "debt" isn't an accurate metaphor for what techical debt really is. The fact that this way of thinking about techical debt "isn't widely known" is exactly the point. Most folks think about techical debt in terms of a thing that must eventually be repaid regardless of the future of the software while presenting it as an uncovered call is much more accurate as to what is actually happening: you're trading a now benefit for the future potential that it will cost you nothing or it could be so expensive that it might cost you everything. The decision to incur technical debt is actually an investment that the benefit now is more valuable than the future cost. Debt is completely different; debt implies that it must, eventually, one day be repaid with interest; however not all technical debt must actually be repaid-- for example if you build feature x in a sloppy but expeditious way, you've incurr d techical debt, however if feature x is eventually depreciated the you "won" because your overall cost of the feature is less than it would have been had you not incurred the techical debt. But, if feature x becomes the center of your product's world and everything else is blocked by the debt, then you lose greatly in comparison to the cost it would have taken to build it debt-free in the first place, thus the risk is theoretically unlimited and not just limited to the amount of technical debt incurred -- because other things are now being delayed because of that debt. So the goal, in my opinion is to manage risk, incur technical debt minimally and only when there's a high probability of that debt not ever having to be repaid. If you know, with a high degree of certainty that the debt will need to be repaid, it's cheaper not to incur it in the first place.
I think the uncovered call metaphor is a brilliant way of framing this issue. It doesn't matter if we know finance or not, it's the way of looking at the problem that provides us with a good framework with which to make development decisions. If we are aware of the unlimited downside and manage that risk, we can actually be more aware of when it makes sense to incur technical debt and when it doesn't. In my opinion, it, just like options trading, is all about risk management and certainly not about traditional debt management.
I totally understand this pain point before I began reading on options I was clueless, mystified but ultimately realized options are akin to trading stocks (buying low selling high) but with the added time restriction and ability to make money in any market.
Options are tricky to understand but essentially, think of it as just a piece of paper or a contract between you and the person buying it from you. It's a buy/sell market that exists on these "papers". Options trading essentially revolve around buying these papers which usually have an expiry date of between weeks to years and at what price you can buy the underlying good before the expiry date. The profit is made from the valuation of this paper going up and down based on the underlying value of what this paper represents. The paper can be contract about beef, corn, oil and share price of Apple. Just like the stock market, you want to pay cheap price for a paper and sell it when it goes high, but the beauty of options is since you don't actually trade the actual good itself, you can create a dizzying array of strategies and combinations to make money in any type of situation, but with the condition that you have to be right about what market we are in (trending up, down, sidways, volatility etc).
Writing an option is like selling a piece of paper that says the person buying your paper will have the ability to buy the stock at the price written on the paper. If the price is low and the stock price goes up, well you now have to buy X number of shares that was written on the paper at the high price to give to this guy, causing great deal of loss to you (since you sold the paper for some cash earlier).
If the stock price falls, then you could buy the shares at the low low price using the money you made from selling the paper and give it to the other guy, who most likely won't ask you to do this and just think about the time he paid you to write him a piece of paper that is now "expired" or worthless.